In early use: acknowledgement of allegiance or subjection; (later) recognition or acknowledgement of something as true, valid, legal, or worthy of…

Acknowledgement of something as true, valid, legal, or worthy of consideration; esp. formal acknowledgement conveying approval or sanction of…

A recognition or appreciation of the value of a duty, quality, or virtue, esp. as a motive or standard for one's own conduct.

Acceptance of the authority, validity, or legitimacy of a person, office, etc.; recognition of a claim; an instance of this.

Acknowledgement.

= recognition, n. Obsolete. rare.